Pump device

ABSTRACT

The pump device has a driving member with one end connected to a diaphragm and another end connected to a driving mechanism. The driving mechanism side end repeats reciprocating motion along first axial direction and oscillation in second axial direction. The diaphragm side end performs the reciprocating motion in the first axial direction, and a problem is that the diaphragm easily deteriorates to be cut in a direction in which the diaphragm can be easily stretched, for example, in the second axial direction for performing oscillation. By embedding the base fabric having the fiber which extends in the second axial direction into the diaphragm, the strength in the second axial direction and the durability can be improved. By providing the index part to indicate the second axial direction, the extending direction of the fiber of the base fabric embedded within the diaphragm becomes distinguishable. In assembling the pump device, it becomes easy to place the diaphragm in a desired direction to the main body of the pump.

TECHNICAL FIELD

The present invention relates to pump devices used as blowers orpressure pumps.

BACKGROUND ART

Pump devices called blowers or pressure pumps are widely known asequipment to increase the pressure of gases such as fuel gas and oxygento a desired pressure. In this kind of pump devices, roots pumps,diaphragm pumps and the like have been used. For example, a diaphragmpump used as a blower for fuel gases in a fuel battery system isdescribed in the following Patent Document 1.

Typically, as materials of diaphragms, elastic materials such as rubbersare used. Because of this, the diaphragm is easy to elastically change,and there are cases that the characteristics as the device would change.Therefore, in order to stabilize the characteristics of the diaphragm, adiaphragm in which a base fabric is provided embedded is described inPatent Document 2.

Patent Document 1: Japanese Patent Application Laid-open No. 2009-47084

Patent Document 2: Japanese Patent Application Laid-open No. Hei10-132077

SUMMARY OF INVENTION Problem To Be Solved By The Invention

In Patent Document 2, the base fabric has been provided embedded inorder to suppress the excessive protrusion, of the outer circumferentialpart of the diaphragm, due to squeezing resulting in elastic change atthe time of caulking by a press. However, in the diaphragm pump, thediaphragm is performing the following reciprocating motion. That is,while a peripheral edge of the diaphragm is supported by a main body ofthe pump, a part thereof is connected to a driving member. By a motionof the driving member made by a driving mechanism, the diaphragmperforms a constant reciprocating motion with stretching, and changesthe volume of a pump chamber. This means that when the diaphragm pumpwas driven for a long time, a failure by deterioration, fatigue andbeing partially cut may occur in a particular part, which is easy to bestretched, of the diaphragm.

In view of the circumstances as described above, an object of thepresent invention is to provide a pump device which is capable ofstabilizing the performance of a diaphragm.

Means For Solving The Problem

To achieve the object described above, according to an embodiment of thepresent invention, there is provided a pump device including a mainbody, a diaphragm and a driving part.

The main body forms a pump chamber for intaking and discharging a fluid.

The diaphragm includes a base material, a base fabric and an index part.The base material is made of an elastic material which has a firstsurface to face the main body in a first axial direction, a secondsurface on a side opposite to the first surface, and a peripheral edgearea supported by the main body. The base fabric is provided embedded inthe base material, at least having a first fiber which extends in asecond axial direction perpendicular to the first axial direction. Theindex part is provided, to the base material to indicate the secondaxial direction.

The driving part includes a driving mechanism and a driving member,which driving member has a first end connected to the second surface anda second end to be connected to the driving mechanism, and which drivingmechanism allows the driving member to reciprocate along the first axialdirection while allowing the driving member to oscillate in the secondaxial direction.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] A cross-sectional view showing a configuration of a pump deviceaccording to an embodiment of the present invention.

[FIG. 2] Diagrams showing a configuration of a main part of thediaphragm, where (A) is a cross-sectional view and (B) is a plan view.

[FIG. 3] A cross-sectional view of the main part for explaining anoperation of the diaphragm pump according to the embodiment of thepresent invention.

[FIG. 4] Cross-sectional views of the main part for explaining a stateof the diaphragm each of which corresponds to (A) and (B) of FIG. 3.

[FIG. 5] An explanatory view showing an example of a plain weave fabric.

[FIG. 6] A plan view of a diaphragm showing a shape of an index partused in another embodiment of the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

A pump device according to an embodiment of the present inventionincludes a main body, a diaphragm and a driving part.

The main body forms a pump chamber for intaking and discharging a fluid.

The diaphragm includes a base material, a base fabric and an index part.The base material is made of an elastic material which has a firstsurface to face the main body in a first axial direction, a secondsurface on a side opposite to the first surface, and a peripheral edgearea supported by the main body. The base fabric is provided embedded inthe base material, at least having a first fiber which extends in asecond axial direction perpendicular to the first axial direction. Theindex part is provided to the base material to indicate the second axialdirection.

The driving part includes a driving mechanism and a driving member,which driving member has a first end connected to the second surface anda second end to be connected to the driving mechanism, and which drivingmechanism allows the driving member to reciprocate along the first axialdirection while allowing the driving member to oscillate in the secondaxial direction.

In the pump device, the diaphragm has the base material made of theelastic material, and the base fabric (reinforcing fabric) is providedembedded to the base material. The diaphragm is allowed to perform areciprocating motion by the driving member connected thereto, in a statewhere the peripheral edge area of the diaphragm is supported by the mainbody. With this reciprocating motion, the diaphragm cyclically changesthe volume of the pump chamber, to intake the fluid into the pumpchamber and to discharge the fluid out from the pump chamber in analternating manner.

One end of the driving member is connected to the diaphragm and anotherend of the driving member is to be connected to the driving mechanism.The driving mechanism is a motor which is a driving source, and a shaftthat is eccentric from a driving shaft of the motor, for example. Theend of the driving member in the driving mechanism side repeats thereciprocating motion along the first axial direction, and theoscillation in the second axial direction, by the driving mechanism. Inconjunction with this, the end in the diaphragm side of the drivingmember performs the reciprocating motion in the first axial direction.Because of this, a problem that the diaphragm is easy to deteriorate tobe cut, in a direction in which the diaphragm can be easily stretched,for example, in the second axial direction for performing oscillation,may arise.

In the pump device, by embedding the base fabric having the fiber whichextends in the second axial direction into the diaphragm, it canincrease the strength thereof in the second axial direction, and thedurability can be improved. Further, by embedding the base fabric whichcan manage the stretching in the second axial direction into thediaphragm, the performance of the diaphragm is stabilized, and thechanges in the volume of the pump chamber is also stabilized, and thusit can stabilize the performance as a pump.

Further, by providing the index part to indicate the second axialdirection, the extending direction of the fiber of the base fabricembedded within the diaphragm becomes distinguishable. Therefore, at thetime of assembling the pump device, it becomes easy to place thediaphragm in a desired direction to the main body of the pump.

The driving member may further have a fixture which includes a supportsurface to face the first surface, and a shaft part formed on thesupport surface, which shaft part penetrates the base material and is tobe coupled to the first end. In addition, index part may be formed to anopening in which the shaft part penetrates.

The index part may be a linear portion perpendicular or parallel to thesecond axial direction forming a part of the opening.

The index part may be a notch which is connected to the opening in adirection perpendicular or parallel to the second axial direction.

By that the index part of the diaphragm is formed to the opening, itbecomes possible to work while checking the desired direction whenplacing the diaphragm to the main body of the pump. Further, the indexpart can be formed easily.

Hereinafter, an embodiment of the present invention will be describedwith reference to the drawings.

FIG. 1 is a cross-sectional view showing a structure of a pump device 3according to an embodiment of the present invention. In this embodiment,the pump device 3 is configured with a diaphragm pump. In FIG. 1, Z-axis(first axis) indicates a vertical direction (gravity direction), andX-axis (second axis) and Y-axis indicate planer directions.

A main body 10 has a casing 11, a pump head 12 and a pump head cover 13.

The pump head 12 has an inlet port 101 and an outlet port 102, and isplaced on a top surface of an annular base 110. The base 110 is attachedto an open end at an upper part of the casing 11, and supports theperipheral edge part of a diaphragm 20 by sandwiching together with thepump head 12. The pump head 12 forms a pump chamber 100 between this andthe diaphragm 20.

A pump head 12 has an inlet passage T1 to contact between the inlet port101 and the pump chamber 100, and has an outlet passage 12 to contactbetween the pump chamber 100 and the outlet port 102. The pump chamber100 is communicable through the inlet passage T1 and the outlet passage12, to the inlet port 101 and the outlet port 102, respectively. In theinlet passage T1 and the outlet passage 12, respectively, an inlet valve103 and an outlet valve 104 are attached.

The pump head cover 13 is attached to an upper part of the pump head 12.Each of the inlet passage T1 and the outlet passage 12 is formed bycombining the pump head 12 and the pump head cover 13. The casing 11,the pump head 12 and the pump head cover 13 are integrally fixed withthe use of a plurality of screw members B.

The casing 11 forms an operating space 105 inside the main body 10 tohouse a connecting rod 32, a bearing 33 and an eccentric cam 34.

FIG. 2 (A) is a cross-sectional view showing a configuration of a mainpart of the diaphragm 20. The Z-axis to indicate the vertical direction,X-axis and Y-axis to indicate the planer directions are shown in FIG. 2as well. The diaphragm 20 has a base material 200 made of an elasticmaterial which has a top surface 201 and a lower surface 203, and areinforcing fabric 202 provided embedded in the base material 200. Theperipheral edge parts of the top surface 201 and the lower surface 203are sandwiched between the base 110 and the pump head 12. However, inFIG. 2 (A), the base 110 and the pump head 12 are omitted.

Each of the top surface 201 and the lower surface 203 is made of asynthetic rubber. Examples of rubber materials to be used may includenitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluorocarbonrubber (FKM), and other rubber materials which are resistant tohydrocarbon gas such as methane and propane. The reinforcing fabric 202is made of synthetic fiber such as nylon (polyamide), for example. Inaddition, the reinforcing fabric 202 and the top surface 201, the lowersurface 203 are integrated by vulcanization bonding or the like.

FIG. 2 (B) is a plan view showing a configuration of a main part of thediaphragm 20. For illustrative purposes, in FIG. 2 (B), some part of thebase material 200 is removed, thereby exposing the reinforcing fabric202. The reinforcing fabric 202 includes a group of fibers F1 parallelto the X-axis. In addition, the reinforcing fabric 202 may furtherinclude a group of fibers F2 crossing the group of fibers F1 as shown.

It should be noted that although the reinforcing fabric 202 is formed inan entire plane of the diaphragm 20, it is not limited thereto. Theshape of the reinforcing fabric 202 is not limited to a circular shape,and for example, may be a symmetrical shape with respect to the X-axisthat passes through the center of the diaphragm 20. The length of thegroup of fibers F1 is not particularly limited either, and may be anylength as long as the strength in the X-axis direction can be increasedsufficiently.

The diaphragm 20 has an index P to indicate the X-axis direction.Typically, the index P shows one of the modes that can be distinguishedthrough the five senses of human such as visual and tactile, butotherwise, the index M may be any mode that can distinguish the X-axisdirection using techniques such as electrical and optical. Further, anarea where the index M is placed is not limited as long as an operatorcan distinguish the index P when placing the diaphragm 20 to the mainbody 10. In FIG. 2 (B) of this embodiment, the index M is an opening 201which has a “D” shape including a linear portion L perpendicular to theX-axis direction. That is, in this embodiment, the directionperpendicular to the linear portion L would be recognized by theoperator as the X-axis direction of the diaphragm 20. It should be notedthat this example is not limitative, but the linear portion L may beformed parallel to the X-axis direction.

A driving part 30 has a fixture 31, the connecting rod 32, the bearing33, the eccentric cam 34 and a driving source 35.

The connecting rod 32 includes a first support surface in contact withthe lower surface 203 of the diaphragm 20, and is fixed to the center ofthe lower surface 203. On the other hand, the fixture 31 has a secondsupport surface in contact with the top surface 201, and a protrusion310 to be fitted to the opening 204 of the diaphragm 20. The protrusion310 may have a plane shape corresponding to the shape of the opening204. The fixture 31 and the connecting rod 32 are assembled in a mannerof vertically sandwiching the diaphragm 20, and, for example, areintegrated thereto via a screw 320. Thus, the fixture 31 and theconnecting rod 32 make up a driving member 300 which drives thediaphragm 20 up and down. It should be noted that the fixture 31 may bewithout the protrusion 310, and the screw 320 may be fitted in theopening 204.

The driving source 35 includes a motor having a rotating shaft 350extending along the Y-axis direction, and the like. A distal end of therotating shaft 350 is attached to the center of rotation of theeccentric cam 34. An end of the connecting rod 32, opposite to the firstsupport surface, is connected to the circumferential surface of theeccentric cam 34 via the bearing 33. The eccentric cam 34 is formed inan eccentric manner with respect to the inner race of the bearing 33 andthe eccentricity gives the reciprocation amount (stroke amount) of thediaphragm 20.

FIG. 3 is a cross-sectional view of the main part of the diaphragm pump3 when viewed from the Y-axis direction, and shows a typical operationof the driving part 30. Although the details of the pump head 12 in thiscase is different from actual one, the configuration of the pump head 12is depicted in the same manner as in FIG. 1 for ease of understanding.

When the rotating shaft 350 is rotated by the driving source 35; the endof the driving member 300 that is connected to the eccentric cam 34performs a reciprocating motion in the Z-axis direction accompanied byan oscillation in the X-axis direction. Simultaneously, since the end ofthe driving member 300 that is connected to the diaphragm 20 performs areciprocating motion in the Z-axis direction, the diaphragm 20 alsoperforms a reciprocating motion in the Z-axis direction.

FIG. 3 (A) shows an example where the rotating shaft 350 and the centerof the eccentric cam 34 are lined in a row in the Z-axis direction, andthe volume of the pump chamber 100 has become minimal (exhaustionprocess). FIG. 3 (B) shows an example where the rotating shaft 350 andthe center of the eccentric cam 34 are lined in a row in the X-axisdirection, and the driving member 300 has descended in the Z-axisdirection while inclining (intake process). In conjunction with this,the diaphragm 20 also descends in the Z-axis direction, and the volumeof the pump chamber 100 becomes larger than in FIG. 3 (A). Thus, withthe movement of the diaphragm 20 in the Z-axis direction, the volume ofthe pump chamber 100 changes. In addition, as shown in FIG. 3 (B), whenthe volume of the pump chamber 100 is increased, suction of gas is madeby closing the outlet valve 104 while opening the inlet valve 103.Conversely, as shown in FIG. 3 (A), when the volume of the pump chamber100 is decreased, compression and conveyance of gas is made by openingthe outlet valve 104 while closing the inlet valve 103.

In the diaphragm 20, fatigue or deterioration may arise in a part whichis easy to be stretched due to the reciprocating motion of the above. InFIG. 4, (A) and (B) schematically show the shapes of the diaphragm 20each corresponding to (A) and (B) of FIG. 3. In FIG. 4, the diaphragm 20is described separately in five areas X1 to X5. Each of X1 and X5 is thearea which is supported by the main body 10; X2 and X4 are the areaswith elastic deformation; and X3 is the area which is supported by oneend of the driving member 300. The areas X1 and X5 belong to a commonannular area of the diaphragm 20. The areas X2 and X4 belong to a commonannular area of the diaphragm 20 as well.

In FIG. 4 (A), X3 is raised in the Z-axis direction with respect to X1and X5, and between X2 and X4 has a stretch. In FIG. 4 (B), X3 islowered in the Z-axis direction with respect to X1 and X5, with astretch between X2 and X4, and further, there is a distortion generatedbetween X2 and X3. This is due to that a stress is applied thereto bythe inclination of the driving member 300, as shown in FIG. 3 (B). Asdescribed above, the diaphragm 20 is easily stretched in the X-axisdirection by the motion shown in FIG. 3. In view of this, by embeddingthe reinforcing fabric 202 having the group of fibers F1 which extendsin the X-axis direction into the diaphragm 20, the strength of thediaphragm 20 can be increased, and the durability can be improved.Further, by managing the stretching of the diaphragm 20, the performanceas the diaphragm is stabilized, and the changes in the volume of thepump chamber 100 is also stabilized, and thus it can stabilize theperformance as a pump.

Examples of weaves of the fabric in which the group of fibers F1 extendsin a parallel manner to the X-axis include a plane weave shown in FIG.5. The plane weave is one in which fibers f2 are alternately combined,in a direction perpendicular to a group of fibers f1 arranged inparallel. By using such a plane-weave reinforcing fabric 202, thestrength in the X-axis direction can be increased, and the durabilitycan be improved. The distance between each fiber, which is the patterndensity of the weave, is not particularly limited but may be any as longas the strength is sufficient.

Meanwhile, since the diaphragm typically has a disc shape, the extendingdirection of the fiber in the embedded reinforcing fabric 202 might beundistinguishable when placing the diaphragm 20 to the main body 10. Inview of this, by using the index M for indicating the X-axis direction,the extending direction of the fiber of the reinforcing fabric 202embedded to the diaphragm 20 becomes distinguishable. Therefore, itbecomes easy to place the diaphragm 20 in a desired direction to themain body 10. For example, when placing the diaphragm 20 having theindex M including the linear portion L, which has been described in thisembodiment, to the main body 10, the diaphragm 20 may be placed in amanner that the linear portion L is parallel to the extending directionof the rotating shaft 350 (Y-axis direction in FIG. 1). In the casewhere the reinforcing fabric 202 further includes the group of fibers F2crossing the group of fibers F1, the linear portion L may be placedeither parallel or perpendicular to the extending direction of therotating shaft 350.

Hereinabove, the embodiment of the present invention has been described,but the present invention is not limited to the above-mentionedembodiment and can be variously modified without departing from the gistof the present invention, as a matter of course.

For example, in the embodiment described above, the index M was theopening 204 having the “D” shape including the linear portion Lperpendicular to the X-axis direction. However, for example, as shown inFIG. 6, the index M may be the opening 204 to which a notch R isconnected in a direction parallel to the X-axis direction. The shape ofthe notch R is not particularly limited as long as it can indicate theX-axis direction, and for example, it may be connected in a directionperpendicular to the X-axis direction. Further, the part to form thenotch R is not specified as long as it is within the opening 204.

In addition, a fluid used in the pump device of an embodiment of thepresent invention is not limited to gas, and may be liquid.

DESCRIPTION OF REFERENCE NUMERALS

3 pump device

10 main body

20 diaphragm

30 driving part

100 pump chamber

101 inlet port

102 outlet port

1. A pump device comprising: a main body forming a pump chamber forintaking and discharging a fluid; a diaphragm including a base materialmade of an elastic material which has a first surface to face the mainbody in a first axial direction, a second surface on a side opposite tothe first surface, and a peripheral edge area supported by the mainbody, a base fabric, provided embedded in the base material, at leasthaving a first fiber which extends in a second axial directionperpendicular to the first axial direction, and an index part, providedto the base material, to indicate the second axial direction; and adriving part including a driving mechanism and a driving member, whichdriving member has a first end connected to the second surface and asecond end to be connected to the driving mechanism, and which drivingmechanism allows the driving member to reciprocate along the first axialdirection while allowing the driving member to oscillate in the secondaxial direction.
 2. The pump device according to claim 1, wherein thedriving member further has a fixture which includes a support surface toface the first surface, and a shaft part formed on the support surface,which shaft part penetrates the base material and is to be coupled tothe first end, and the index part is formed to an opening in which theshaft part penetrates.
 3. The pump device according to claim 2, whereinthe index part is a linear portion, perpendicular or parallel to thesecond axial direction, forming a part of the opening.
 4. The pumpdevice according to claim 2, wherein the index part is a notch which isconnected to the opening in a direction perpendicular or parallel to thesecond axial direction.
 5. The pump device according to claim 1, whereinthe base fabric further includes a second fiber which extends in a thirdaxial direction crossing the second axial direction within the firstsurface.